Both ethernet and wireless not working

Dear all,

I am aware there are a few threads with similar problems, but I haven't found a solution in there.
I just installed ubuntu (Dual boot with Windows) in a Dell laptop (Studio 1535) and both the ethernet and wireless are unable to connect.

The wireless is activated but it does not find any of the available wireless networks.
The ethernet tries to connect, but disconnects before completing the connexion.